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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Performance of a horizontal roughing filtration system for the pretreatment of greywater

Mtsweni, Sphesihle January 2016 (has links)
Submitted in fulfillment for the requirements of the degree of Master of Engineering, Department of Chemical Engineering, Durban University of Technology, KwaZulu-Natal, South Africa, 2016. / A large fraction of the world's population, around 1.1 billion people, do not have access to acceptable sources of water. In South Africa there is a growing pressure on the available freshwater resources. New sources of freshwater supply are becoming increasingly scarce, expensive or politically controversial. This has led to large scale interest in the application of water reclamation and reuse of domestic, mining and industrial wastewater as an alternative water supply sources. This is becoming critical to sustain development and economic growth in the Southern African region. This research aims at providing both social and scientific information on the importance of greywater reuse and recycling as an alternate source to aid water demand management under South African conditions. The approach to this research work was divided into two main thrusts: the first was to gain an understanding of the public attitudes towards the idea of reusing greywater that is usually perceived as wastewater which pose health concerns. The second was to provide an understanding of typical greywater quality in a peri-urban community in Durban, South Africa as well as investigate the suitability of a horizontal roughing filtration system in reducing pollutant strength of contaminants found in greywater for non-potable reuse applications. In order to achieve the central aim of this research study, the following objectives were considered: • Investigation of public perception and attitudes towards the reuse of greywater. • Determination of greywater quality in a peri-urban community in Durban South Africa. • Investigation of the performance of a horizontal roughing filtration system for the treatment of greywater collected from a peri-urban community in Durban, South Africa. It was important to have an understanding of public perception and attitudes towards the reuse of greywater because of the fact that the success of any reuse application depends on the acceptance of the public. The methodological approach for this aspect of the research work involved administering of structured questionnaires to residents within the community through field visits. The questionnaire addressed issues related to attitudes towards the reuse of greywater, perceived advantages related to the reuse of greywater and concerns related to public health issues regarding the reuse of greywater. The successful implementation of any greywater treatment process depends largely on its characteristics in terms of the pollutant strength. The methodological approach for this aspect of the research work involved physico- chemical characterization of the greywater collected from different sources within the households in the peri-urban community. Greywater samples were collected from the kitchen, shower and laundry within each of the households. This aspect of the research work was undertaken to gain an understanding of greywater quality from different sources within and between households. In order to achieve the third objective of this research work, a pilot plant horizontal roughing filtration system was designed and fabricated for the treatment of greywater. The system consisted of three compartments containing different sizes of gravel that served as the filter media. This was done in order to investigate the effect of varying filter media size on the performance of the horizontal roughing filtration system in treating greywater. The system had an adjustable manual valve used in varying the filtration rate. The impact of varying filtration rate on the performance of the horizontal roughing filtration system in treating greywater was also investigated. The main findings of this research were: • From the survey conducted, the percentage of the public willing to accept the reuse of greywater within the community was far higher than the percentage opposing its reuse. Concerns have often been expressed by the public that the reuse of greywater could pose possible adverse effects to public health. However, in this pilot study it was found that a higher percentage of respondents (>60%) disagree that the reuse of greywater could negatively impact on public health compared to less than 20% of the respondents that agree. An interesting finding of this study was that a greater percentage of the respondents were willing to have a dual water distribution system installed in their current place of residence. • The physico-chemical characterization of greywater from different sources within the households investigated indicated that, the quality of greywater varies considerably between all sources and from household to household. None of the households investigated produced the same quality of greywater. It was also found that greywater generated from the kitchen contains the most significant pollutants in terms of the physico-chemical parameters considered in this study compared to the other sources within the household. • The pilot plant horizontal roughing filtration system demonstrated its suitability for the treatment of greywater for non-potable reuse applications. It was observed that 90% turbidity and 63% Chemical Oxygen Demand reduction was achieved over the entire duration of operation of the horizontal roughing filter. It was also observed that the removal efficiency was significantly higher in the compartment with the smallest filter media size and the removal efficiency was significantly higher at lower filtration rates. It is therefore concluded from the investigation conducted in this research that the role of the public is a vital component in the development and implementation of any reuse system / application. It was found that there was a relatively high level of acceptance for the reuse of greywater among the respondents within the community where the study was conducted. The greywater characteristics results obtained from this investigation indicated the necessity of treatment prior to disposal in the environment. Also, a low BOD5/COD ratio of 0.24, which is significantly lower than 0.5, is an indication that the greywater generated from the community cannot be easily treated using biological treatment processes and/or technologies. The pilot horizontal roughing filtration system used for the treatment of greywater in this study demonstrated its suitability for the treatment of greywater for non-potable reuse applications such as irrigation, toilet flushing and washing activities. / M
32

Quantifying and predicting hydrological responses of water quality associated with land cover changes within the upper Vaal River, South Africa

23 April 2015 (has links)
Ph.D. (Geography) / South Africa is characterised by limited natural water resources and is water-stressed. The Upper Vaal Water Management Area (WMA) is part of the Vaal River system, which is deemed to be the ‘workhorse’ of South Africa as it is located in the economic heart of the country. The WMA supplies water to all of the major economic entities in the economic hub of the country and is fully exploited in terms of the water that it makes available. Owing to its prime importance in terms of the economic development of the country, the quality of the water in the Upper Vaal WMA is an important factor which needs to be investigated and monitored intensively. The degradation in the quality of the water in this region will in its turn reduce the availability of water in the Upper Vaal WMA and have widespread environmental, social, as well as economic consequences and impacts. The aim of this study is thus to quantify and predict future hydrological responses, in terms of water quality, towards land cover changes in the case of the Upper Vaal WMA for the period, July 2000 to June 2012. In so doing, model equations can be formulated and predictions can be made for future hydrological changes in terms of future concentrations of the selected water quality parameters linked to specific land cover change scenarios. The quality of the water in the Upper Vaal WMA varies significantly across all of the secondary and tertiary catchments and could, therefore, be described as being of a heterogeneous nature. Its quality as a whole is below average and in some cases, poor. The quality of the water in the secondary catchment of the Wilge River, on the other hand, is for the most part of an ideal to acceptable standard. However it has been degraded to a certain extent as it displays tolerable concentrations of phosphate, COD and Chlorophyll a and unacceptably high concentrations of nitrate. The Vaal River, Vaal River Barrage and the Mooi River catchments are significantly degraded owing to the mainly tolerable to unacceptably high concentrations of most of the selected water quality parameters that they contain.....
33

An assessment of the social impacts of water pollution on children in informal settlement : the case of Kliptown informal settlement, Soweto, Johannesburg

Kamusono, Jennifer Tadzei 09 1900 (has links)
The study investigated the causes of water pollution in Kliptown, an informal settlement 17km south of Johannesburg. The study further examined the impact of water pollution, sanitation and inadequate and low quality water provision on children’s social life, health and well-being in informal settlements. The subject of water pollution due to inadequate water supply and sanitation is one that brings a lot of debate, due to the overwhelming impacts it has on children’s social life as well as their health. In informal settlements, social impacts arising from inadequate water supply and sanitation such as the prevalence of water-related diseases like diarrhoea, skin rashes and eye infections have become a permanent feature. This study aimed at assessing the social impacts of water pollution in Kliptown’s Tamatievlei, Mandela View and Valentine Village informal settlements. It also looked at the factors that contribute to the social impacts of water pollution and propose recommendations on how to minimise the social impacts of water pollution on children in Kliptown’s informal settlements. The study applied a mixed method approach, utilising exploratory and descriptive questions to extrapolate both qualitative and quantitative data, which was also presented in quality and quantity form. Outcomes of the investigation indicated that diarrhoea is a major waterborne disease that affects children, mostly under-five years of age, in the informal settlements and that children sometimes missed school due to their being treated for diarrhoea and other water-related illnesses. It was also found that children lived in unhygienic conditions with smelling bucket system toilets and rotting garbage. The study established that children congregated for water at water points for long periods and in the process, they were deprived of time to take part in other social activities. The study recommends mitigating inadequate, low quality water supply, water pollution and sanitation in an integrated manner to gradually eliminate the negative social impacts on children’s social life, health and well-being in Kliptown informal settlement. / Environmental Science / M.Sc. (Environmental Management)
34

Establishing biological and environmental drivers that influence the health assessment index as a biomonitoring tool

Phala, Balance Matseilane January 2019 (has links)
Thesis (MSc.) Zoology)) -- University of Limpopo, 2019 / In South Africa, a high anthropogenic demand of water for domestic, recreational, agricultural, urbanisation and industrial purposes has placed enormous pressure on freshwater resources and has led to a decline in water quality. In addition to measuring water quality variables, the health assessment index (HAI) advocated by AvenantOldewage and Swanepoel (1993), and modified by Crafford and Avenant-Oldewage (2009) by incorporating the inverted parasite index (IPI), and adapted further by Madanire-Moyo et al. (2012) who excluded the white blood cells counts, has been used as a rapid and inexpensive means of assessing and monitoring fish health and, in turn, the state of aquatic ecosystems. However, few studies have evaluated the latter approach in conjunction with other biomonitoring indices to assess the water quality of impoundments. Thus, the aim of this study was twofold. The first was to evaluate the HAI adapted by Madanire-Moyo et al. (2012) as a means to establish the health status of Oreochromis mossambicus (Peters, 1852) sampled from various impoundments based on a once-off survey. The second was to establish if the adapted HAI, in conjunction with selected biomonitoring indices and environmental variables, could describe monthly and seasonal fluctuations of O. mossambicus health. Once-off surveys were conducted between April and May 2016 at five impoundments. The Luphephe-Nwanedi Dam located in the upper catchment of the Limpopo River System and Rhenosterkop Dam situated in the Elands River, a tributary of the Olifants River System, served as control sites due to little or no anthropogenic activities occurring in their catchment areas. In addition, surveys were conducted at Loskop and Flag Boshielo dams and Phalaborwa Barrage situated in the main stem of the Olifants River for comparison purposes. The latter three impoundments were selected because they vary in water quality and pollution levels. Monthly surveys were carried out at Flag Boshielo Dam from February 2016 to February 2017 to establish if the biomonitoring tools and the quantification of water and sediment quality variables, could describe and predict seasonal fluctuations in the health of O. mossambicus. To this end, water quality variables were measured during each survey. Water and sediment samples were collected for analysis of nutrients and metals. Oreochromis mossambicus were collected using gill nets. Fish health was assessed using the adapted HAI that was based on observing parasite burden, haematocrit determination and anomalies in body tissues and organs in conjunction with determining gonad and iv hepato-somatic indices, the condition factor, blood glucose levels, microscopy analyses of fish gills and metal concentrations in fish muscle tissues. Water quality in terms of pH, total dissolved solids and electrical conductivity, nutrients and some aqueous and sediment metals exhibited significant differences (p ˂ 0.05) between impoundments surveyed with water quality from good to poor being in the order of: Luphephe-Nwanedi Dams ˂ Rhenosterkop Dam ˂ Loskop Dam ˂ Phalaborwa Barrage ˂ Flag Boshielo Dam. The HAI scores varied significantly (p ˂ 0.0001) between impoundments and substantiated water quality variables results during once off surveys, indicating that the health of fish from Flag Boshielo Dam were most affected when compared to the health of fish surveyed from the other impoundments. Findings from monthly surveys conducted at Flag Boshielo Dam indicated better conditions in terms of water quality variables during a period of high inflow as opposed to periods of low inflow. The HAI scores obtained for fish exhibited significant (p ˂ 0.0001) differences between the months surveyed and were found to be in agreement with the water quality findings, indicating that flow regimes and water quality of an impoundment have an impact on fish health. The condition and somatic indices findings did not seem to be sensitive enough to discriminate between the impoundments during the once off surveys. While during monthly surveys, these indices were significantly (p ˂ 0.0001) different between the months, showing to be affected by seasonal fluctuations. Knowledge of the HAI in conjunction with blood glucose levels, gill histopathology and the arithmetic mean thickness of gill epithelium (Har) best described the health of fish in both the once off and monthly surveys. In conclusion, the findings of this study emphasised the HAI premise that fish from more polluted sites would be more impacted as opposed to less impacted sites, making the HAI adapted by Madanire-Moyo et al. (2012) an effective and rapid biomonitoring tool that can be used in the field. Furthermore, this study proved that the HAI can be used either solely or in association with the parasite index (PI) or IPI depending on the objectives of the study, as no pronounced differences were evident when using HAI, HAI with PI and HAI with IPI. / National Research Foundation (NRF) and Water Research Commission (WRC)
35

The impact of water and sediment quality on the health of Oreochromis Mossambicus (Peters, 1852) and Schilbe Intermedius Ruppell, 1832 at the Phalaborwa Barrage in the Olifants River

Gohell, Ashla Fiona January 2014 (has links)
Thesis (MSc. (Zoology)) -- University of Limpopo, 2014 / The Olifants River is presently one of the most threatened river systems in South Africa. The Upper and Middle catchments are heavily impacted by anthropogenic activities, however little is known of the status of the river in the Lower catchment in the Limpopo Province. Thus the aim of this study was to evaluate the impact of water quality on the health of Oreochromis mossambicus and Schilbe intermedius at the Phalaborwa Barrage. This was achieved through assessing the water (seasonally) and sediment quality (bi-annually) at three sites in the Phalaborwa Barrage (inflow, middle and the wall). Ten specimens of each of the two selected fish species were seasonally collected using gill nets of different mesh sizes from May 2010 to January 2011. The water, sediment and the dorsal muscle tissues from both fish species were analysed for selected metals at an accredited laboratory by means of ICP-OES spectrometry and the human health risk factor upon consumption of fish contaminated with metals was assessed. Fish health was determined at the field laboratory by applying the HAI, PI and IPI. In addition, the condition factor (CF) was determined for the selected fish species during all seasons. All water constituents with the exception of turbidity during spring (wall), anions (Cl, F and SO4) and cations (Ca, K, Mg and Na) fell within the target water quality range (TWQR) for aquatic ecosystems throughout the study. Inorganic nitrogen concentrations showed eutrophic (spring) and oligotrophic conditions (autumn, winter and summer), while phosphorus indicated eutrophic (autumn, winter and spring) and hypertrophic (summer) conditions throughout the study. There was no significant difference in anions (F=0.07; df=3; p=0.97), cations (F=0.57; df=3; p=0.64) and nutrients (F=0.79; df=3; p=0.56) detected in water. The metals that were detectable in the water samples were: Al, Fe, Sn, B, Sr, Se, Ba, Mn, Sb and As, while in sediment all metals (Fe, Al, Ti, Mn, Ba, B, Zn, Ag, V, Cr, Ni, Sr, Sn, Co, Cu, Cd, Pb, As and Sb) were detected with the exception of Se. The average metal concentrations detected above the TWQR are; Al, Fe, Se, Sn, Sb and As, in the sediment only Cr and Cd were above suggested quality guidelines. There was no significant difference in metals detected in water (F=0.05; i df=3; p=0.98) and sediment (F=1.62; df=1; p=0.21). Higher HAI values were recorded for S. intermedius than O. mossambicus, indicating that O. mossambicus was in better health than S. intermedius. For S. intermedius, parasites contributed the most to the total HAI followed by abnormal liver conditions, haematocrit levels (internal variables) and abnormal gills (external variable). While for O. mossambicus, parasites, liver, haematocrit (internal variables), gills, eyes, fins and skin (external variables) contributed to the HAI values. There was no significant difference in HAI values for O. mossambicus (F=1.9; df=3; p=0.15) and S. intermedius (F=2.58; df=3; p=0.66) throughout the study. The PI and IPI for ectoparasites for both fish species, were higher than the PI for endoparasites. There was a significant difference for PI values of O. mossambicus (F=0.07; df=3; p=0.041) and S. intermedius (F=3.65; df=3; p=0.019) during the study. Oreochromis mossambicus had higher CF values than S. intermedius and both fish species had values that indicated good fish. Metals that were detectable in O. mossambicus muscle tissue included: Ba, B, Zn, Fe, Sr, Al, Mn, Cr, Ag, Pb, Ni, Cu, Se, V, Sb, Ti, Sn and Co, while for S. intermedius Ba, B, Zn, Fe, Al, Cr, Sr, Mn, Cu, As, Pb, Se, Sn, Ag, Ti, Ni, Sb and Co were recorded. There was no significant difference in bioaccumulation levels between the two fish species (F=1.412; df=3; p=0.250). The human health risk assessment indicated that fish muscle tissues are unsuitable for continuous (weekly/daily) consumption. As some carcinogenic metals i.e. Pb, Cr and Sb for O. mossambicus and Pb, As and Cr for S. intermedius were detected at HQ levels of more than 50 times the recommended value of one. In conclusion, the Phalaborwa Barrage is impacted by metals (Al, Fe, Se, Sn, Sb and As) and occasionally with nutrients. The water and sediment quality and metal bioaccumulation have confirmed the latter statement and to a lesser extent the HAI, PI and IPI. The human risk assessment done indicated that continuous consumption of fish by humans, especially O. mossambicus may have adverse effects on the health of humans.
36

A measure of service quality on water in Lepelle-Nkumpi Municipality in the Limpopo Province

Shongwe, Nkosinathi Sipho January 2007 (has links)
Thesis (MBA.) -- University of Limpopo, 2007 / The residents of Lebowakgomo in Lepelle-Nkumpi Municipality experience numerous inequalities in relation to water services provision. Some of the residents protest towards the inequalities through refusal to pay for the water services. The confrontational non paying residents field questions which the municipality can hardly answer. The problem of refusal to pay is of the magnitude that recently the municipality had to go house-to-house pleading with the inhabitants to pay if the municipality was to continue to provide water services. The specific objectives of this study were three-fold: (1) to determine water service quality using residents’ perceptions on water services in Lebowakgomo, (2) to determine residents’ expectations and perceptions on water services in Lebowakgomo, and (3) to determine the residents’ perceptions on water service quality and customer satisfaction in Lebowakgomo using age, gender, qualification and suburb. A questionnaire comprising five dimensions, namely, tangibles, reliability, assurance, empathy and responsiveness, was compiled to collect data from three suburbs of Lebowakgomo in Lepelle-Nkumpi Municipality. The original sample size was 120, with 9 becoming spoiled due to missing data. The independent variables comprised age, qualification, suburb and gender. Most of the data were analysed for kurtosis and skewness and with the exception of one variable, the rest of the data did not conform to parametric analysis criteria. The major findings of this study indicated overall negative perceptions of residents’ on four dimensions of empathy, reliability, responsiveness and assurance on water service quality which implied that the residents were dissatisfied with the service and called on management to use SERVQUAL as a valid model of assessment to identify areas requiring immediate attention for service improvement. On the other contra positive it was revealed that the municipality was doing well on the tangibles dimension. ix The study recommended use of SERVQUAL in measuring quality of other services within the constitutional competencies of the municipality and further research to investigate age contribution to service quality.
37

Ecological status of the Sand River after the discharge of sewage effluent from the Polokwane and Seshego wastewater treatment works

Seanego, Koena Gloria January 2014 (has links)
Thesis (M.Sc. (Aquaculture)) -- University of Limpopo, 2014 / Population growth in urban areas is putting pressure on sewage treatment plants. The improper treatment of sewage entering the aquatic ecosystems causes deterioration of the water quality of the receiving water body. The effect of sewage effluent on the Sand River was assessed. Eight sampling sites were selected, site 1 and 2 were upstream of the of the sewage treatment plant along the urbanised area of Polokwane, whilst sites 3, 4, 5, 6, 7 and 8 were downstream. The physicochemical parameters and coliform counts in the water samples were determined. Macroinvertebrate abundances and diversity (H') was determined at the different sites during the dry and rainy season. The water quality status of the Sand River with respect to the South African scoring system (SASS) scores and average score per taxon (ASPT) was determined. A linear regression was performed to test the correlation of the SASS scores with abundance and H'. Heavy metal concentrations in water, sediment, grass (Ishaemum fasciculatum) and fish (Oreochromis mossambicus) at the sites were evaluated. The suitability of the Sand River and surrounding borehole water for irrigation was also determined. Hierarchical average linkage cluster analysis produced two clusters, grouping two sites above the sewage treatment works and six sites downstream of the sewage effluent discharge point. Principal component analysis (PCA) identified total nitrogen, total phosphorus, conductivity and salinity as the major factors contributing to the variability of the Sand River water quality. These factors are strongly associated with the downstream sites. Canonical correspondence analysis (CCA) indicated that Chironomidae family was found on the nitrogen gradient during the dry season. However during the rainy season, Chironomidae was found in the centre of the ordination which indicated that it was ubiquitous. Escherichia coli levels (1463.73 counts/100ml) in the maturation ponds of Polokwane wastewater treatment works could potentially lead to contamination of the Polokwane aquifer. High diversity was recorded at the sites before discharge and the sites further downstream. There was significant correlation (P<0.05) between the SASS scores and macroinvertebrate diversity during the dry season (R2=0.69) and the rainy season (R2=0.77). Fish samples had significantly higher (P<0.05) iron and copper concentrations, while the vi sediment had significantly higher lead concentration (P>0.05). The United States salinity laboratory (USSL) diagram indicated that the sodium hazard (SAR) and alkalinity hazard (conductivity) was low and the Sand River and borehole water was suitable for irrigation. The residual sodium carbonate (RSC) was below 1.24 meq/l, also indicating that both the Sand River and borehole water is still suitable for irrigation. The total phosphorus concentrations fluctuated across the different site. Total nitrogen concentrations showed a gradual decrease downstream from the point of discharge. The coliform levels also showed a gradual decrease downstream. This shows that the river still has a good self-purification capacity.
38

Impacts of sugarcane farming on coastal wetlands of the north coast of Zululand, Kwadukuza, South Africa

Matavire, Melisa M. 04 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Wetlands are key to providing important ecosystem goods and services yet they are under threat from a number of anthropogenic activities. In particular, in this study area, agriculture in the form of sugarcane farming is a threat to wetlands as sugarcane is reliant on a good water supply. The impacts of sugarcane farming emanates from the fact that sugarcane is a mono crop that requires wetland resources and uses a lot of pesticides and fertilisers. Despite the assumed contribution of sugarcane farming to wetland loss and degradation, few studies have quantitatively assessed the spatio-temporal changes in wetland extent as well as changes in water quality because of this activity. This study assesses the impacts of sugarcane farming on wetland extent and water quality in two coastal wetlands of KwaDukuza, North coast of Zululand, South Africa. Specifically this study sought to (i) assess the impacts of sugarcane farming on the spatial extent of wetlands between 1959 and 2012, (ii) determine if sugarcane farming negatively affect water quality within the wetlands and (iii) evaluate the perceptions of local farmers regarding impacts of sugarcane farming on wetlands. Results of the study indicated an increase in the extent of Zinkwazi sugarcane fields from 62.3% to 67% between 1959 and 1989 and Nonoti sugarcane fields’ extent increased from 50.5 % to 56.4% between 1959 and 2000. The last decade from the year 2000 showed gradual decrease in the area of wetland farmed by sugarcane due to the global sugar price remaining static while the cost of farming inputs increased and due to conversion of some farms to urban developments. Unfortunately, this has not lead to an increase in wetland area as the waterfront type developments, as well as a formal settlement have replace the sugarcane in the wetlands. Water was analysed for nitrogen (N), phosphorus (P) and potassium (K) and results for both Zinkwazi and Nonoti indicated an increasing trend of N and P from upstream to the middle region of the rivers and a decreasing trend of the N and P from the middle region to downstream. Sugarcane farming does not take place below the middle region and so does not provide fresh sources of these nutrients. The downstream area where the N and P decrease also coincides with the area of the river under tidal influence such that the N and P are being diluted by the incoming tidal seawater. K showed an increasing trend from upstream to downstream and its values were higher than N and P. Concentrations of N and P above the South African water quality guidelines for aquatic ecosystem were recorded in the middle region. Furthermore, farmers’ perceived wetlands to have been transformed to agricultural land and related these changes to their sugarcane farming activities. It can thus, be concluded that sugarcane farming has resulted in wetland loss as well as deterioration of water quality within the Zinkwazi and Nonoti wetlands in KwaDukuza. In that regard, there isneed to engage farmers in wetland management programs in order to reduce the negative environmental impacts associated with sugarcane farming in wetlands. / AFRIKAANSE OPSOMMING: Vleilande is die sleutel tot die verskaffing van ‘n belangrike ekosisteem dienste, maar hulle is onder ‘n bedreiging deur 'n aantal menslike aktiwiteite. In besonder in hierdie studie area, is Argriculture in die vorm van suikerriet boerdery is bedraging vir vleilande, en suikerriet is afhanklik van 'n goeie watervoorraad. Ten spyte van die veronderstelde bydraes van suikerriet boerdery, is die vleiland aan die agteruitgang, 'n Paar studies het kwantitatief die tydruimtelike veranderinge in die vleiland, sowel as veranderinge in die gehalte van water as gevolg van hierdie aktiwiteit waargeneem. Spesifiek is hierdie studie gepoog om (i) te bepaal wat die impak van suikerriet boerdery op die ruimtelike omvang van die vleiland tussen 1959 en 2012 is, (ii) bepaal of suikerriet boerdery negatief beïnvloed is deur die gehalte van water in die vleilande en (iii) die persepsies van plaaslike boere rakende die evalueering en impak van suikerriet boerdery op die vleilande. Resultate van die studie het aangedui 'n toename in die omvang van Zinkwazi suikerriet velde van 62,3% tot 67% tussen 1959 en 1989, en die Nonoti suikerriet velde toegeneem het met 50,5% tot 56,4% tussen 1959 en 2000. Die laaste dekade van die jaar 2000 het geleidelike afname in die area van die vleilande getoon, omdat suikerriet as gevolg van die globale suiker prys die koste van boerdery-insette verhoog het, en dit het gelei tot die omskakeling van 'n paar plase na stedelike ontwikkelings. Ongelukkig het dit nie gelei tot 'n toename in die vleiland gebiede nie, met die gevolg die waterfront tipe ontwikkelings, asook 'n formele nedersetting, vervang die suikerriet in die vleilande. Water is ontleed vir N, P en K en resultate vir beide Zinkwazi en Nonoti, het aangedui 'n toenemende tendens van stikstof en Fosfor. Dit gaan stroomop na die middel-streek van die riviere en 'n dalende neiging van die N en P uit die middel streek stroomaf. Suikerriet boerdery vind nie plaas onder die middel streek nie, en so is daar nie vars bronne, wat van hierdie voedingstowwe verskaf nie. Die stroomaf gebied waar die N en P ‘n afname het, val ook saam met die gebied van die rivier onder die gety , en dit beinvloed sodanig dat die N en P se water verdun word deur die inkomende gety se seewater. K het 'n toenemende neiging van stroomop en stroomaf en sy waardes is hoër as van die N en P. Konsentrasies van N en P bo die Suid-Afrikaanse water standaard riglyne is in die middel streek aangeteken. Verder, beskou boere dat die vleilande behoort te verander om die landbougrond en verwante veranderinge aan hul suikerriet boerdery en aktiwiteite. Ons kan dus aflei dat suikerriet boerdery het gelei tot die vleiland se verlies asook die verandering in die watergehalte in die Zinkwazi en die Nonoti vleilande in KwaDukuza. In dié verband is dit nodig dat die boere in die vleiland by programme betrek word ten einde die negatiewe omgewingsimpakte wat met suikerriet boerdery gepaard gaan in vleilande te verminder.
39

Microbial ecology of the Buffalo River in response to water quality changes

Zuma, Bongumusa Msizi January 2010 (has links)
South Africa’s freshwater quality and quantity is declining and consequently impacting on the ecological health of these ecosystems, due to increased agricultural, urban and industrial developments. The River Health Programme (RHP) was designed for monitoring and assessing the ecological health of freshwater ecosystems in South Africa, in order to effectively manage these aquatic resources. The RHP utilises biological indicators such as in-stream biota as a structured and sensitive tool for assessing ecosystem health. Although the RHP has been widely implemented across South Africa, no attempts have been made to explore microbial ecology as a tool that could be included as one of the RHP indices. This study used selected microbial responses and water physico-chemical parameters to assess the current water quality status of the Buffalo River. This study showed that water quality impairments compounded in the urban regions of King William’s Town and Zwelitsha and also downstream of the Bridle Drift Dam. The results also showed that the lower and the upper catchments of the Buffalo River were not significantly different in terms of water physico-chemistry and microbiology, as indicated by low stress levels of an NMDS plot. Though similarities were recorded between impacted and reference sites, the results strongly showed that known impacted sites recorded the poorest water physico-chemistry, including the Yellowwoods River. However, the Laing Dam provided a buffer effect on contributions of the Yellowwoods River into the Buffalo River. Multivariate analysis showed that microbial cell counts were not influenced by water physico-chemical changes, whilst microbial activity from the water and biofilm habitats showed significant correlation levels to water physico-chemical changes. This study demonstrated that further investigations towards exploitation of microbial activity responses to water physico-chemical quality changes should be channelled towards the development of microbiological assessment index for inclusion in the RHP.
40

The establishment of a routine monitoring technique for detecting the most prevalent pathogenic viruses in river water, Western Cape, South Africa

Saayman, Michael John January 2012 (has links)
Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Biomedical Technology in the Faculty of Health and Wellness Sciences at the Cape Peninsula University of Technology, 2012 / In many developed countries worldwide the provision of safe, clean water is an expected commodity. In South Africa however, as in most developing countries, the access and supply of water safe for human consumption is challenged or complicated by pollution and more recently water availability. Point-source pollutants in surface- and groundwater are normally the most concentrated closest to the pollutant source (such as the end of a pipe or an underground injection system). Examples of point-source pollution are commercial and industrial businesses, that often discharge waste such as solvents and heavy metals from their operations. In contrast, non-point-source pollution occurs due to runoff moving across or through the ground and absorbing and accumulating pollutants which eventually end up in streams, rivers and dams. The lack of waste removal and adequate sanitation facilities results in the disposal of faecal matter and sewage into storm water drains which flow directly into the river systems contributing to the incidence of diseases such as gastroenteritis, diarrhoea and chronic lung ailments, caused by waterborne pathogenic bacteria, viruses and fungi. Routine water quality analysis however, does not include monitoring for viral contaminants, as this process is hampered by the lack of simple, reliable, time- and cost-effective testing methods to concentrate and detect viral pathogens. The primary aim of this study was thus to establish and optimise routine monitoring techniques for the detection of rota-, adeno- and enteroviruses in the Berg- and Plankenburg Rivers, Western Cape. Initially, various concentration and extraction methods were compared for the optimum recovery of viruses from spiked water samples. One hundred milliliter water samples were spiked with one milliliter rotavirus and two milliliters adenovirus control virions (Coris Bioconcept, Gembloux, Belgium). Optimisation testing of enterovirus was however, not completed due to the unavailability of a positive control. Four viral concentration techniques, namely the Silicon dioxide (SiO2) method, positively charged, negatively charged and the mixed-ester filters, were compared. Various nucleic acid extraction methods were also employed to establish which method would provide optimum yields for both DNA and RNA nucleic acids. The extraction techniques included the TRIzol method (Invitrogen, California, USA) for RNA extraction, the Roche High Pure PCR Template Preparation kit (Roche, Mannheim, Germany) for DNA extraction, and the QIAamp Ultrasens Virus kit (Qiagen GmbH, Hilden, Germany) for simultaneous RNA and DNA extraction. The use of virus specific primers within the PCR technique was also optimised. In addition, gene specific primers and oligo(dT)15 primers were tested and compared to establish which primers would yield the best results since gene specific primers are said to be more sensitive than oligo(dT)15 primers (van Pelt-Verkuil et al., 2008) when synthesising cDNA (rotavirus). The SiO2 concentration method yielded variable results when it was used with the various nucleic acid extraction techniques in this study, since positive PCR results were obtained when used in combination III with some techniques, while negative results were obtained with others. Similarly, variable results were also obtained when negatively charged filters were used to concentrate virus particles, and when this method was used in conjunction with various virus nucleic acid extraction techniques to identify different viruses by RT-PCR and PCR. Results for the non-charged mixed-ester filter were comparable to the positively charged filters when used in conjunction with the various nucleic acid extraction techniques in this study. Both these techniques yielded the highest viral particle concentration from the spiked water samples. Pilot study results indicated the presence of rotavirus and adenovirus detected by RT-PCR and PCR respectively, when filtering through the positively charged filter. The positively charged filter/QIAamp UltraSens virus kit combination was found to be the optimum combination when analysing the spiked water results and was then employed for the concentration of virus particles in the river water samples collected from the Plankenburg- and Berg River systems throughout the study period. The expected PCR product of 346 bp for rotavirus was absent in all 72 river water samples analysed for both river systems. In contrast to the PCR results obtained for rotavirus, the expected product of 261 bp for adenovirus was detected in 22 (30.5%) samples collected throughout the study period. Fifteen of the 22 adenovirus positive samples were found in the Plankenburg River (distributed over all sites), while seven of the 22 adenovirus positive samples were found in the Berg River (all sites). A nested PCR was used to detect enterovirus in the river water samples collected from both river systems throughout the study period. In the first round of the enterovirus PCR 15 river water samples (at various sites for both river systems) yielded a faint 513 bp product. Further amplification by nested PCR then yielded 13 (18.1%) positive nested PCR products of 297 bp. The incidence of adenovirus and enterovirus in river waters reported in the current study and the Van Heerden et al. (2003) investigation motivates for similar studies to be conducted in drinking water, dam water used for recreational purposes as well as rainwater, which is gaining popularity as a sustainable water source.

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